Space-based radio echo sounding of the continental ice sheets can potentially provide full coverage with uniform sampling and data quality as well as detection of change in environmentally sensitive areas. This research addresses the feasibility of sounding the Antarctic ice sheets with a space-based P-band radar. The assessment makes use of an electromagnetic model of the ice sheets where most of the model parameters are estimated from data that have been acquired in Antarctica with an airborne P-band ice sounding radar. The performance of a nadir-looking space-based radar (which is similar to the radar of ESA’s Biomass mission) is simulated for a set of Antarctic scenarios that are defined based on the statistics of key ice regions. It is found that in about two thirds of the simulation scenarios clutter and/or thermal noise will obscure the signal from the ice bed.